Using STORE, LOAD, BUFFER - Storing and Reading data from QVD files - QlikView Tutorial - Session 15
In this session you will learn about Using STORE, LOAD, BUFFER - Storing and Reading data from QVD files
QVD(Qlikview Data File)
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QVD is a Qlikview native Data Format
It is written to and Read from Qlikview Only
It is optimized for Speed
Benefits of QVD Files
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Increasing Load Speed
Reducing burden on Database Servers
Reducing Network Traffic
Consolidating Data from multiple Qlikview Applications
Useful to implement Incremental Load Process
Structure of QVD File
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XML Header
Symbol Tables
Actual Table Data
QVD Modes
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Standard Mode
Super Fast Mode
Customer - changes/transformations - Customer.qvd(Standard )
Customer - Nochanges/Notransformations - Customer.qvd(super Fast Mode)
Standard Mode
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If we create QVD File after making some changes or transformations to the source Database table, then the QVD is Standard Mode or Fast Mode
Unoptimized Load
Super Fast Mode
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If we create QVD File without making any changes or Transformations to the source Database table, then the QVD is in Super Fast Mode
Optimized Load (or) Optimized QVD
Creating QVD Files
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Manually by using STORE Command
Automatically by using Buffer Prefix
Explicitly from Layout
Manually by using STORE Command
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Store Tablename into QVDName.qvd(qvd);
Store * From TableName into QVDName.qvd(qvd);
Store Field1,field2,... From TableName into QVDName.qvd(qvd);
Example
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Products - Products.qvd
Store Products into Products.qvd(qvd);
Store * From Products into Products1.qvd(qvd);
Store ProductID,ProductName From Products into Products2.qvd(qvd);
Store ProductID as [Product ID],ProductName as [Product Name] From Products into Products3.qvd(qvd);
Reading Data from QVD Files
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Load * From Products.qvd(qvd);
Load ProductID,UnitCost From Products.qvd(qvd);
Load ProductID as [Product ID], UnitPrice as [Unit Price] From Products.qvd(qvd);
(or)
Table files Button
Automatically By Using Buffer Prefix
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Encrypted Name
AppData Folder
Buffer Load * .........................;
Buffer (stale after 7 Days) Load * ............;
Buffer (Incremental) Load * ...........................;
Default Location
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C:\Users\Username\AppData\Local\QlikTech\QlikView\Buffers
Explicitly From Layout
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Right click on sheet Object - Export - Under Save as Type, Select Qlikview Data File(*.qvd) - Give Name - ok